A broad convolution on the convexity of the frontal lobe of the cerebrum between the inferior frontal sulcus and the sylvian fissure, divided by branches of the sylvian fissure into three parts; inferior frontal gyrus.

A convolution on the convexity of each frontal lobe of the cerebrum running from front to back between the superior and inferior frontal sulci; middle frontal gyrus.

A broad convolution running from front to back on the medial edges of the convex surface and of each frontal lobe; superior frontal gyrus.